Thermal management system for vehicles with an electric  powertrain

ABSTRACT

This patent application is directed to thermal management systems of vehicles with an electric powertrain. More specifically, the battery system and one or more powertrain components and/or cabin climate control components of a vehicle share the same thermal circuit as the battery module through which heat can be exchanged between the battery module and one or more powertrain or climate control components as needed.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/923,232, filed on 3 Jan. 2014, the entire contents of which areincorporated herein by reference. This application is related to theU.S. patent application Ser. No. 13/763,636, filed on 9 Feb. 2013,entitled BATTERY SYSTEM WITH SELECTIVE THERMAL MANAGEMENT, which isincorporated by reference herein for all purposes.

BACKGROUND

Thermal management is critical to designing and operating electrifiedvehicles. Various components of vehicles, such as the powertrain [e.g.,the engine, transmission, battery system, electric motor(s), motor powerelectronics, battery power electronics, on-board battery charger, 12VDC-DC converter] and climate control (e.g., cabin heat exchanger, andA/C compressor) components all have, respectively, preferred operatingtemperature ranges. For these components to function properly,efficiently, or optimally, thermal management systems are required tocool or heat these components appropriately and rapidly.

In electrified vehicles which include an internal combustion engine(ICE) (i.e., hybrid vehicles or plug-in hybrid vehicles), two thirds ofthe heat generated by the engine is typically wasted. While conventionalsecondary (i.e., rechargeable) batteries are adversely affected whenthis wasted engine heat is directly absorbed by the battery, certain newsecondary batteries, which optimally operate at higher temperatures ascompared to those for conventional batteries, can benefit by acceptingthis wasted heat and being warmed thereby. While conventional thermalmanagement systems exist, systems are still needed to efficiently andrapidly exchange heat between these new secondary batteries and thevarious components of vehicle that can accept or donate heat energy. Assuch, there are needs in the field to which the instant inventionpertains related to thermal management systems for electric vehicleswhich include these new secondary batteries as well as to improvementsto conventional thermal management systems.

The instant disclosure provides, in part, solutions to theaforementioned challenges, as well as others, associated with exchangingheat with secondary batteries and other vehicle components.

SUMMARY

In one embodiment, set forth herein is a thermal management system for avehicle with an electric drivetrain. This system includes a batterysystem including at least one battery cell having a cycle life of atleast 100 cycles, and an optimal operating temperature between about 40°C. and 150° C. In some examples, this system includes a battery systemincluding at least one battery cell having a cycle life of at least 100cycles, and an optimal operating temperature of about 75° C. or higher.In certain examples, this system includes a battery system including atleast one battery cell having a cycle life of at least 100 cycles, andan optimal operating temperature above 75° C. In some examples, thissystem also includes an internal combustion engine (ICE). This systemalso includes a shared thermal circuit thermally coupling the batterysystem to other vehicle components, wherein the thermal circuit includesa working fluid, at least one switch or valve for controlling thetransfer of the working fluid, wherein a control system actuates the atleast one switch or valve, and at least one external heat exchanger; anda control system for controlling the heat exchange between the batterysystem and these other components of the vehicle.

In a second embodiment, set forth herein is a thermal management systemfor a vehicle with an electric drivetrain. The system includes a controlsystem, a shared thermal circuit comprising a working fluid and one ormore switches. In some examples, conductive solids can be substitutedfor the working fluid, in which case the switches and values open andclose the thermal connections to the conductive solids. The one or moreswitches are configured to operate based on signals received from thecontrol system. The system also includes a battery system having a cyclelife of at least 100 cycles and an optimal operating temperature betweenabout 40° C. and 150° C. In some examples, this system includes abattery system including at least one battery cell having a cycle lifeof at least 100 cycles, and an optimal operating temperature of about75° C. or higher. In some of these examples, the battery system isthermally coupled to the thermal circuit. Additionally, in someexamples, the system includes an internal combustion engine modulethermally coupled to the thermal circuit and the battery system via theshared thermal circuit, and at least one external heat exchangerthermally coupled to the thermal circuit. In certain examples, theexternal heat exchanger may optionally be removed from the thermalcircuit. The control system is configured to cause the heat dissipatedby the internal combustion engine module to transfer to the batterymodule through the shared thermal circuit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-B are simplified diagrams illustrating a thermal managementsystem according to embodiments set forth herein.

FIG. 2 is a simplified diagram illustrating an alternative thermalmanagement system according to an embodiment set forth herein.

FIGS. 3A-C are simplified diagrams illustrating a thermal managementsystem in series configuration according to embodiments set forthherein.

FIGS. 4A-B are simplified diagrams illustrating operation of a thermalmanagement system where engine heat is advantageously used by thebattery system during cold start according to an embodiment set forthherein. The arrows in FIG. 4B illustrate one flow pattern that ispossible for this system. Depending on which valves are actuated, otherflow patterns are possible.

FIGS. 5A-B are simplified diagrams illustrating operation of a thermalmanagement system where the battery system bypasses the heat exchangerand thermal energy is preserved within the system, according to anembodiment set forth herein. The arrows in FIG. 5B illustrate one flowpattern that is possible for this system. Depending on which valves areactuated, other flow patterns are possible.

FIGS. 6A-B are simplified diagrams illustrating operation of a thermalmanagement system where battery system heat is rejected via externalexchanger according to an embodiment set forth herein. The arrows inFIG. 6B illustrate one flow pattern that is possible for this system.Depending on which valves are actuated, other flow patterns arepossible.

FIGS. 7A-B are simplified diagrams illustrating operation of a thermalmanagement system in an electric vehicle according to an embodiment setforth herein. The arrows in FIG. 7B illustrate one flow pattern that ispossible for this system. Depending on which valves are actuated, otherflow patterns are possible.

FIGS. 8A-B are simplified diagrams illustrating operation of a thermalmanagement system with a shared thermal path where climate controlmodule draws heat from various powertrain components according to anembodiment set forth herein. The arrows in FIG. 8B illustrate one flowpattern that is possible for this system. Depending on which valves areactuated, other flow patterns are possible.

FIGS. 9A-B are simplified diagrams illustrating thermal managementsystem while disengaged from the heat exchanger module according to anembodiment set forth herein. The arrows in FIG. 9B illustrate one flowpattern that is possible for this system. Depending on which valves areactuated, other flow patterns are possible.

FIGS. 10A-B are simplified diagrams of a thermal management system withbidirectional flow control according to an embodiment set forth herein.The arrows in FIG. 10B illustrate one flow pattern that is possible forthis system. Depending on which valves are actuated, other flow patternsare possible.

FIGS. 11A-D are simplified diagrams illustrating operation of a thermalmanagement system where the thermal loop that includes severalpowertrain components can be thermally separated into a first thermalpath for first group of powertrain components, according to embodimentsset forth herein.

DETAILED DESCRIPTION

Embodiments are directed to thermal management systems of electrifiedvehicles, such as plug-in hybrid electric (PHEV) and electric vehicles(EV; e.g., battery electric vehicles). More specifically, the batterysystem, one or more additional powertrain components (e.g. including butnot limited to the engine, transmission, battery system, electric motor,motor power electronics, battery power electronics, on-board batterycharger, 12V DC-DC converter), and/or cabin climate control components(e.g. including but not limited to the cabin heat exchanger, and A/Ccompressor) of a vehicle share a single thermal circuit or loop. Thethermal management system is designed to enable a plurality ofcomponents to operate on a single thermal circuit and exchange thermallyenergy between the battery system, other powertrain components andoptionally climate control components as needed.

By utilizing a shared thermal circuit with batteries capable ofoperating at high temperatures (e.g., solid state conversion chemistrybatteries or batteries having a solid-state electrolyte), the batterysystem and, for example, the combustion engine can directly andefficiently be in fluid and thermal communication. In some examples,battery heat can be directly used to warm up a combustion engine,combustion engine heat can be directly used to warm up a battery system(or one or more batteries within a battery system), battery heat can bedirectly used to provide cabin heat, or all combinations thereof. Asingle or simple thermal circuit allows for a faster rate of heating andcooling, as less components are needed. Using the systems and methodsset forth herein, a second or separate thermal circuit (e.g., includingadditional heat exchangers, pumps, controllers, and valves, asnon-limiting examples) is therefore removed from, or renderedunnecessary for, the system. In some examples, the heat exchangerpassively dissipates heat. In yet other examples, the heat exchangeractively removes heat from the system, or battery, in particular, via aheat pump.

The batteries set forth herein can operate at a high temperature,thereby allowing novel heat utilization via the shared thermal circuit,set forth in the instant disclosure, between an engine, battery system,transmission, battery system, electric motor(s), motor powerelectronics, battery power electronics, on-board battery charger, 12VDC-DC converter] and climate control, cabin heat exchanger, and A/Ccompressor, components and/or other powertrain components. For example,an internal combustion engine (“ICE”) can emit tens of kilowatts ofwaste heat in operation. By utilizing a shared thermal circuit designaccording to embodiments set forth herein, waste heat from thecombustion engine can be utilized to heat the battery system to itsoptimal operating temperature range. Similarly, the battery system canutilize the heat radiated from the radiator sized for the combustionengine heat rejection, reducing vehicle cost and improving heatrejection efficiency.

In a specific embodiment, a thermal circuit is configured to transferheat from the ICE to the battery, and vice versa. Heat transfer isaccomplished, for example, by using a heat transfer fluid (e.g.,typically a water-glycol mixture that has a high specific heatcapacity), which is circulated by one or more pumps. For example, thepump is controlled by a controller module, which causes the pump tocirculate fluid heated by the ICE to the battery when the ICE has a hightemperature and the battery is below a threshold temperature. As a partof the thermal path, switches and/or valves are used to control the flowof the heat transfer fluid. For example, after the battery reaches adesired operating temperature, valves can be used to isolate thecombustion engine and battery system to stop heat transfer or dissipateheat to the ambient environment or air.

With a single thermal circuit, components (e.g. heat exchanger, pump,heat transfer fluid, and the like) of the thermal circuit are shared,thereby reducing system cost, weight, and volume. In a competitiveautomotive original equipment manufacturer (OEM) market, reducing systemcomponents and saving hundreds of dollars can have significant economicimpact. Significant price elasticity exists in the automotive market,where small changes in price can have significant impact on vehiclesales volumes. Consequently, there is a need for automotive OEMs toreduce costs of all vehicle components, especially in instances wheresystem performance can be held constant or improved. For example, theinstantly disclosed shared thermal management system, which can modulatethe heat of certain or all powertrain components (inclusive of thebattery system), is a novel and substantial improvement in vehicledesign for vehicles with electrified powertrains.

By reducing components such as a heat exchanger, pump, and transferfluid, more batteries can be assembled in a given volume thus providingmore energy and power to a drive train. In some examples, this canincrease the driving range. In other examples, this can increaseavailable power with respect to the vehicle's operating temperaturerange.

The overall weight of the vehicle is reduced, increasing performance andefficiency. The weight of a vehicle can be reduced by about 4 kg, about8 kg, about 12 kg or about 3-15 kg in total by removing secondarythermal circuit components. In addition to the weight savings, thereincludes a space savings as well. As much as 15-20 L of space can bereclaimed or utilized when vehicle thermal management systems aredesigned as set forth herein. The additional space allows for efficientand flexible design of related or unrelated vehicle components. Theamount of space reclaimed can be about 5 L, about 10 L, about 15 L orabout 4 L-20 L of space, for example. As the battery system is heatedmore quickly and effectively, performance of the battery systemincreases. In some examples, the thermal circuits herein heat a batteryat least 2-10 times faster than conventional heating systems.Conventional heaters can heat at about 3-5 kW. However, the thermalcircuits herein, in some examples, directly heat a secondary batteryusing the ICE's dissipated heat at about 10 kW or higher.

In addition, a reduced number of components can improve systemreliability and reduce maintenance costs. In various embodiments,transfer of waste heat from the engine to the battery module in coldstart scenarios reduces or eliminates battery module energy expenditurerequired for self-warming and can result in a shorter time until theelectric drivetrain can take over operation of the vehicle. In variousembodiments, a radiator suitable for heat rejection from a combustionengine is oversized relative to the radiator designed solely for abattery system. Consequently, by sharing the radiator, the batterysystem can utilize enhanced heat rejection capability in the sharedsystem, resulting in increased system efficiency, longer component life,and/or improved vehicle performance. By sharing components and usesthereof, other components can be eliminated or reduced in size as well.

Lithium ion and lithium metal batteries are utilized in automotiveapplications because of their high specific energy and energy density,long cycle life, high round trip efficiency, low self-discharge and longshelf life. However, soaked to cold temperatures that vehiclesencounter, lithium ion and lithium metal cells exhibit poor lowtemperature performance. As an example, it has been reported thatlithium ion cells can lose up to 88% of their room temperature capacityat −40° C. The limited power and capacity observed for batteries at lowtemperatures is particularly problematic for all solid state batteries.

Poor low temperature performance, in the worst scenario, can impactvehicle safety where sufficient energy and power from the battery moduleis not available for driving, e.g. when merging onto a freeway, and inthe best scenario, low vehicle performance levels, and/or driver waittimes. Consequently, automotive vehicle manufacturers (OEMs) oftenprovide more power and/or capacity than required during most temperatureconditions to satisfy low temperature requirements, thereby adding cost,weight, and volume to the powertrain. In certain designs, lowperformance levels at cold operating temperatures may not be acceptablebecause they significantly and negatively impact vehicle functionality.In some other designs, the vehicle may rely on the combustion engine (ifpresent) to start and operate the vehicle until the battery modulereaches operating temperature, limiting the utility of the electricpowertrain.

In some examples, set forth herein is a thermal system architecturewhere the battery system shares the same thermal management circuit withother powertrain components (e.g. including but not limited to theengine, transmission, battery module, electric motor, motor powerelectronics, battery power electronics, on-board battery charger, 12VDC-DC converter), and/or cabin climate control components (e.g.including but not limited to the cabin heat exchanger, and/or A/Ccompressor). As an example, the terms “shared thermal circuit”,“combined thermal circuit”, “single thermal loop”, “direct thermalcircuit” and “common thermal circuit” refer to a configuration where theheat transfer fluid or heat transfer materials are shared among thebattery system and one or more powertrain components (e.g. including butnot limited to the engine, transmission, electric motor(s), motor powerelectronics, battery power electronics, on-board battery charger, 12VDC-DC converter) and/or cabin climate control components (e.g. includingbut not limited to the cabin heat exchanger, and A/C compressor), of avehicle.

Battery

In some examples, set forth herein is a battery system including one ormore battery cells connected in series and/or in parallel to provideelectrical power to the vehicle. Battery cells of a battery system mayor may not be homogenous depending on the design of the battery system.An example of a battery system with different cell types may includecells with high power and/or excellent low temperature performance (e.g.due to a cell chemistry or architecture optimized for power or lowtemperature) to handle peak power requirement and cold start scenariostogether with cells optimized for energy density to enable higher energycapacity. For example, the combinations of primary and boost batteries,set forth in U.S. patent application Ser. No. 13/763,636, filed on 9Feb. 2013, entitled BATTERY SYSTEM WITH SELECTIVE THERMAL MANAGEMENT,which is incorporated by reference herein for all purposes, arenon-limiting examples of battery systems with different cell types.

Depending on the implementations, there can be several variations of thethermal system set forth herein that combine the heat transfer circuitof the battery module and the one or more powertrain components (e.g.including but not limited to the engine, transmission, battery module,electric motor, motor power electronics, battery power electronics,on-board battery charger, and/or 12V DC-DC) and/or cabin climate controlcomponents (e.g. including but not limited to the cabin heat exchanger,and/or A/C compressor). Because the battery systems set forth herein cannot only tolerate, but optimally perform at high temperatures, thesebattery systems can be thermally coupled in a shared or simple thermalcircuit, in a way which would adversely affect the performance ofconventional secondary batteries. In some examples, the hightemperatures are temperatures above room temperature. In some otherexamples, the high temperatures are temperatures about 35° C. In otherexamples, the high temperatures are temperatures about 40° C. In yetother examples, the high temperatures are temperatures about 45° C. Insome other examples, the high temperatures are temperatures about 50° C.In some examples, the high temperatures are temperatures about 55° C. Insome other examples, the high temperatures are temperatures about 60° C.In some other examples, the high temperatures are temperatures about 65°C. In other examples, the high temperatures are temperatures about 70°C. In yet other examples, the high temperatures are temperatures about75° C. In some other examples, the high temperatures are temperaturesabout 80° C. In some examples, the high temperatures are temperaturesabout 85° C. In some other examples, the high temperatures aretemperatures about 90° C.

In some examples, set forth herein is a battery system comprising atleast one battery cell having a cycle life of at least 100 cycles, andan optimal operating temperature between about 40° C. or higher. In someexamples, set forth herein is a battery system comprising at least onebattery cell having a cycle life of at least 100 cycles, and an optimaloperating temperature between about 50° C. or higher. In some examples,set forth herein is a battery system comprising at least one batterycell having a cycle life of at least 100 cycles, and an optimaloperating temperature between about 60° C. or higher. In some examples,set forth herein is a battery system comprising at least one batterycell having a cycle life of at least 100 cycles, and an optimaloperating temperature between about 70° C. or higher. In some examples,set forth herein is a battery system comprising at least one batterycell having a cycle life of at least 100 cycles, and an optimaloperating temperature between about 75° C. or higher. In some examples,set forth herein is a battery system comprising at least one batterycell having a cycle life of at least 100 cycles, and an optimaloperating temperature between about 80° C. or higher.

In some examples, the high temperatures are temperatures above roomtemperature. In some other examples, the high temperatures aretemperatures above 35° C. In other examples, the high temperatures aretemperatures above 40° C. In yet other examples, the high temperaturesare temperatures above 45° C. In some other examples, the hightemperatures are temperatures above 50° C. In some examples, the hightemperatures are temperatures above 55° C. In some other examples, thehigh temperatures are temperatures above 60° C. In some other examples,the high temperatures are temperatures above 65° C. In other examples,the high temperatures are temperatures above 70° C. In yet otherexamples, the high temperatures are temperatures above 75′C. In someother examples, the high temperatures are temperatures above 80° C. Insome examples, the high temperatures are temperatures above 85° C. Insome other examples, the high temperatures are temperatures above 90° C.

The battery systems set forth herein, in some examples, are placed inclose proximity, immediately adjacent or in physical contact withcomponents of the thermal circuit, e.g., an internal combustion engine.In some examples, close proximity includes one half the length of anelectric vehicle in which the battery and internal combustion engine arelocated. In some examples, close proximity includes one quarter thelength of an electric vehicle in which the battery and internalcombustion engine are located. In some examples, close proximityincludes one eighth the length of an electric vehicle in which thebattery and internal combustion engine are located. In some examples,close proximity includes one tenth the length of an electric vehicle inwhich the battery and internal combustion engine are located. In someexamples, close proximity includes one sixteenth the length of anelectric vehicle in which the battery and internal combustion engine arelocated. In some examples, close proximity includes one twentieth thelength of an electric vehicle in which the battery and internalcombustion engine are located. In some examples, close proximityincludes one thirtieth the length of an electric vehicle in which thebattery and internal combustion engine are located. In some examples,close proximity includes less than one half the length of an electricvehicle in which the battery and internal combustion engine are located.In some examples, close proximity includes less than one quarter thelength of an electric vehicle in which the battery and internalcombustion engine are located. In some examples, close proximityincludes less than one eighth the length of an electric vehicle in whichthe battery and internal combustion engine are located. In someexamples, close proximity includes less than one sixteenth the length ofan electric vehicle in which the battery and internal combustion engineare located. Merely as an example, shared thermal management systemsinclude, but are not limited to, the following:

-   -   1. A battery system thermal loop combined with thermal loops of        one or more of the following: internal combustion engine,        transmission, battery module, electric motor(s), motor power        electronics, battery power electronics, on-board battery        charger, 12V DC-DC, other powertrain components, cabin climate        control, and A/C compressor;    -   2. A thermal loop including a battery module and other        powertrain components connected in-series or in parallel; and    -   3. Components arranged in different order to optimize operation.

In some examples, battery cells that are capable of operating at hightemperatures are used. High temperature includes operating temperaturesfrom about 80° C. to about 120° C. High temperature includes above 80°C., 80° C. to 100° C., 90-110° C., over 100° C., and about 85-115° C.,as examples. In some examples, rechargeable battery cells utilizing asolid state electrolyte capable of operating at high temperatures areimplemented as a part of the shared thermal circuit technology. It is tobe understood that there may be different types of rechargeable batterycells capable of operating at high temperatures.

Examples of solid state electrolytes suitable for use with thedisclosure herein include those found in International PCT PatentApplication No. PCT/US14/38283, entitled SOLID STATE CATHOLYTE ORELECTROLYTE FOR BATTERY USING Li_(A)MP_(B)S_(C) (M=Si, Ge, AND/OR Sn),filed May 15, 2014, the contents of which are incorporated by referencein their entirety. Examples of solid state electrolytes suitable for usewith the disclosure herein include those found in International PCTPatent Application No. PCT/US2014/059575, entitled GARNET MATERIALS FORLI SECONDARY BATTERIES AND METHODS OF MAKING AND USING GARNET MATERIALS,filed Oct. 7, 2014, the contents of which are incorporated by referencein their entirety. Secondary batteries that include these solid stateelectrolytes are well suited for the thermal management systems setforth herein.

Examples of high temperature battery and battery systems suitable foruse with the thermal management systems set forth herein include, butare not limited to those found in U.S. Published patent application Ser.No. 13/922,214, entitled NANOSTRUCTURED MATERIALS FOR ELECTROCHEMICALCONVERSION REACTIONS, and Ser. No. 13/749,706, entitled SOLID STATEENERGY STORAGE DEVICES, filed on Jun. 19, 2013 and Jan. 25, 2013,respectively. The disclosures of which are herein incorporated byreference in their entireties. Other examples include those found inU.S. Provisional Patent Application No. 62/088,461, entitled CATHODEWITH NANOCOMPOSITE PARTICLE OF CONVERSION CHEMISTRY MATERIAL AND MIXEDELECTRONIC IONIC CONDUCTOR, filed Dec. 5, 2014. Other examples includethose found in U.S. Provisional Patent Application No. 62/096,510,entitled LITHIUM RICH NICKEL MANGANESE COBALT OXIDE (LR-NMC), filed Dec.23, 2014. The contents of these applications are incorporated byreference in their entirety.

Solid state conversion chemistry batteries are well suited for use withthe thermal management systems set forth herein and often perform wellat high temperatures. Some examples of solid state conversion chemistrybattteries include transistion metal fluoride batteries. Hybridconversion chemistry and intercalation batteries are also suitable foruse with the thermal management systems set forth herein.

In some examples, a positive electrode material can be characterized byparticles or nanodomains having a median characteristic dimension ofabout 20 nm or less. These include (i) particles or nanodomains of ametal selected from the group consisting of iron, cobalt, manganese,copper, nickel, bismuth and alloys thereof, and (ii) particles ornanodomains of lithium fluoride.

In one implementation, the metal is iron, manganese or cobalt and themole ratio of metal to lithium fluoride is about 2 to 8. In anotherimplementation, the metal is copper or nickel and the mole ratio ofmetal to lithium fluoride is about 1 to 5. In certain embodiments, themetal is an alloy of iron with cobalt, copper, nickel and/or manganese.

In certain embodiments, the individual particles additionally include afluoride of the metal. In some cases, the positive electrode materialadditionally includes an iron fluoride such as ferric fluoride. Forexample, the metal may be iron and the particles or nanodomains furtherinclude ferric fluoride.

In some examples, the positive electrode useful with the high operatingtemperature batteries and battery cells described herein includes one ormore materials selected from conversion chemistry material, such as, butare not limited to, LiF, Fe, Cu, Ni, FeF₂, FeO_(d)F_(3−2d), FeF₃, CoF₃,CoF₂, CuF₂, NiF₂, where 0≤d≤0.5, and the like, materials set forth in inU.S. Patent Publication No. 2014/0117291, filed Oct. 25, 2013, andentitled METAL FLUORIDE COMPOSITIONS FOR SELF FORMED BATTERIES,materials set forth in in U.S. Provisional Patent Application No.62/038,059, filed Aug. 15, 2014, entitled DOPED CONVERSION MATERIALS FORSECONDARY BATTERY CATHODES, materials set forth in in U.S. PatentApplication Publication No. 2014/0170493, entitled NANOSTRUCTUREDMATERIALS FOR ELECTROCHEMICAL CONVERSION REACTIONS, and filed Jun. 19,2013 as U.S. patent application Ser. No. 13/922,214, and materials suchas, but not limited to NCA (lithium nickel cobalt aluminum oxide), LMNO(lithium manganese nickel oxide), NMC (lithium nickel manganese cobaltoxide), LCO (lithium cobalt oxide, i.e., LiCoO₂), nickel fluoride(NiF_(x), wherein x is from 0 to 2.5), copper fluoride (CuF_(y), whereiny is from 0 to 2.5), or FeF_(z) (wherein z is selected from 0 to 3.5).

The positive electrode material can additionally include (iii) aconductive additive. In some cases, the conductive additive is a mixedion-electron conductor. In some cases, the conductive additive is alithium ion conductor. In some implementations, the lithium ionconductor is or includes thio-LISICON, garnet, antiperovskite, lithiumsulfide, FeS, FeS₂, copper sulfide, titanium sulfide, Li₂S—P₂S₅, lithiumiron sulfide, Li₂S—SiS₂, Li₂S—SiS₂—Li, Li₂S—SiS₂—Al₂S₃, Li₂S—SiS₂—GeS₂,Li₂S—SiS₂—P₂S₅, Li₂S—P₂S₅, Li₂S—GeS₂—Ga₂S₃, or Li₁₀GeP₂S₁₂.

In some examples of batteries suitable for use with the thermalmanagement systems set forth herein, the positive electrodes can becharacterized by the following features: (a) a current collector; and(b) electrochemically active material in electrical communication withthe current collector. The electrochemically active material includes(i) a metal component, and (ii) a lithium compound component intermixedwith the metal component on a distance scale of about 20 nm or less.Further, the electrochemically active material, when fully charged toform a compound of the metal component and an anion of the lithiumcompound, has a reversible specific capacity of about 350 mAh/g orgreater when discharged with lithium ions at a rate of at least about200 mA/g. In some cases, the electrochemically active material isprovided in a layer having a thickness of between about 10 nm and 300

In some examples of batteries suitable for use with the thermalmanagement systems set forth herein, the positive electrode additionallyincludes a conductivity enhancing agent such as an electron conductorcomponent and/or an ion conductor component. Some positive electrodesinclude a mixed ion-electron conductor component. The mixed ion-electronconductor component can contain less than about 30 percent by weight ofthe cathode. Examples of the mixed ion-electron conductor componentinclude thio-LISICON, garnet, lithium sulfide, FeS, FeS₂, coppersulfide, titanium sulfide, Li₂S—P₂S₅, lithium iron sulfide, Li₂S—SiS₂,Li₂S—SiS₂—LiI, Li₂S—SiS₂—Al₂S₃, Li₂S—SiS₂—GeS₂, Li₂S—SiS₂—P₂S₅,Li₂S—P₂S₅, Li₂S—GeS₂—Ga₂S₃, and Li₁₀GeP₂S₁₂. In some embodiments, themixed ion-electron conductor component has a glassy structure.

In some examples of batteries suitable for use with the thermalmanagement systems set forth herein, the lithium compound component isselected from lithium halides, lithium sulfides, lithium sulfur-halides,lithium oxides, lithium nitrides, lithium phosphides, and lithiumselenides. In one example, the lithium compound component is lithiumfluoride. In a further example, the lithium compound component islithium fluoride and the metal component is manganese, cobalt, copper,iron, or an alloy of any of these. In some positive electrodes, thelithium compound component contains particles or nanodomains having amedian characteristic length scale of about 5 nm or less. In certainembodiments, the lithium compound component includes an anion that formsa metal compound with the metal on charge, and the metal compound andlithium ions undergo a reaction to produce the metal and the lithiumcompound component, and the reaction has a Gibbs free energy of at leastabout 500 kJ/mol.

In some examples of batteries suitable for use with the thermalmanagement systems set forth herein, the batteries are characterized bythe following features: (i) an anode, (ii) a solid-state electrolyte,and (iii) a cathode including (a) a current collector, (b)electrochemically active material in electrical communication with thecurrent collector. In these examples, the electrochemically activematerial includes (i) a metal component, and (ii) a lithium compoundcomponent intermixed with the metal component on a distance scale ofabout 20 nm or less. Further, the electrochemically active material hasa reversible specific capacity of about 600 mAh/g or greater whendischarged with lithium ions at a rate of at least about 200 mA/g at 50°C. between 1 and 4V versus a Li.

In some examples of batteries suitable for use with the thermalmanagement systems set forth herein, the anode, solid state electrolyte,and cathode, together provide a stack of about 1 μm to 10 μm thickness.In some of these designs, the electrochemically active material isprovided in a layer having a thickness of between about 10 nm and 300nm.

In some examples, the electrochemically active material has a reversiblespecific capacity of about 700 mAh/g or greater when discharged withlithium ions at a rate of at least about 200 mA/g. In some examples, thedevice has an average voltage hysteresis less than about 1V when cycledat a temperature of 100° C. and a charge rate of about 200 mAh/g ofcathode active material.

In another aspect, the disclosure pertains to battery devicescharacterized by the following features: (a) an anode region containinglithium; (b) an electrolyte region; (c) a cathode region containing athickness of lithium fluoride material configured in an amorphous state;and (d) a plurality of iron metal particulate species spatially disposedwithin an interior region of the thickness of lithium fluoride to form alithiated conversion material. Further, the battery device has an energydensity characterizing the cathode region of greater than about 80% of atheoretical energy density of the cathode region. In certainembodiments, the first plurality of iron metal species is characterizedby a diameter of about 5 nm to 0.2 nm. In certain embodiments, thethickness of lithium fluoride material is characterized by a thicknessof 30 nm to 0.2 nm. In some cases, the thickness of lithium fluoridematerial is homogeneous. In certain embodiments, the cathode region ischaracterized by an iron to fluorine to lithium ratio of about 1:3:3. Incertain embodiments, the cathode region is characterized by an iron tofluorine to lithium ratio from about 1:1.5:1.5 to 1:4.5:4.5.

In some examples, with the structure described above, the device canhave an energy density of between 5 and 1000 Wh/kg, an energy density ofbetween 10 and 650 Wh/kg, or an energy density of between 50 and 500Wh/kg. In certain embodiment, an energy density can greater than 50Wh/kg, or greater than 100 Wh/kg.

Definitions

As used herein, “control system”, refers to a device, or set of devices,that manages, commands, directs or regulates the behavior of otherdevices or systems. Control systems include, but are not limited to, acomputer, a microprocessor, a microcontroller or a logic circuit, thatactuate the valves and switches in the thermal circuit in order topermit the working fluid, therein, to flow in one direction or anotherdirection, or not at all. In certain instances, the microprocessor canbe a field programmable gate array (FPGA). Control systems can alsoinclude temperature responsive devices (e.g., a thermostat) which sendsor receives signals depending on the temperature of the components ofthe control system or the system controlled by the control system. Insome examples, the control system may include a temperature-activatedvalve apparatus.

As used herein, “control module,” refers to an enclosure containingcircuit boards preprogrammed with software containing the logic used todetermine responses to various sensor inputs. The controller modulesoftware has output signals which can actuate pumps or valves atintervals according to its internal logic.

As used herein, “heat exchanger”, refers to a device for transferringheat from one medium to another. Examples of heat exchangers includeradiators, which can include coils, plates, fins, pipes, andcombinations thereof.

As used herein, the phrase “battery cell” shall mean a single cellincluding a positive electrode and a negative electrode, which haveionic communication between the two using an electrolyte. In someembodiments, the same battery cell includes multiple positive electrodesand/or multiple negative electrodes enclosed in one container.

As used herein, the phrase “battery system” shall mean an assembly ofmultiple battery cells packaged for use as a unit. A battery system mayinclude any number of battery cells. These cells may be interconnectedusing in series connections, parallel connections, and variouscombinations thereof.

As used herein, the phrase “optimal operating temperature,” shall, inthe context of a battery cell, mean the temperature at which the batterycell is capable of outputting greater than 50% power of the rated powerfor the battery cell. In certain examples, the “optimal operatingtemperature,” shall, in the context of a battery cell, mean thetemperature at which the battery cell operates at a peak efficiencywhile meeting automotive safety and life requirements.

As used herein, “fluid”, refers to gases, liquids, gels and combinationsthereof. A cooling fluid, or coolant, assists in transferring heatwithin a thermal circuit. In some examples, a solid conductor may besubstituted for a heat transfer fluid.

As used herein, “switch”, refers to a device for making and breaking theconnection in an electric circuit.

As used herein, “thermally coupled”, refers to two or more components ordevices in communication, such that they are capable of exchanging(i.e., receiving or dissipating) heat between two or more of thecomponents or devices. Thermally coupled devices can be in closeproximity or separated by pipes or other medium for transferring orexchanging heat.

As used herein, a “thermal loop,” refers to a circuit including at leasta circulating fluid, one or more pumps, a heat exchanger, optionally anelectric fluid heater, and optionally valves to control flow. In someexamples, the thermal loop optionally includes a port to fill the loopwith fluid, and also optionally a reservoir tank. The thermal loopfunctions to transport and direct heat to or from the battery and, ifnecessary, reject this heat to another loop or directly to ambient air.

As used herein, “powertrain”, refers to one or more of an engine,transmission, battery system, electric motor(s), motor powerelectronics, battery power electronics, on-board battery charger, and12V DC-DC converter.

As used herein, “dissipate”, refers to dispersing, passively andspontaneously. In some examples here, heat is received or dissipatedpassively and without energy actively being expended using the thermalmanagement systems set forth herein.

As used herein, “drivetrain”, refers to the system in a motor vehiclethat connects the transmission to the drive axles. A hybrid vehicle caninclude an electric drivetrain, for example.

As used herein, “conversion chemistry”, refers to a material thatundergoes a chemical reaction during the charging and discharging cyclesof a secondary battery. For example, a conversion material can includeLiF and Fe, FeF₃, LiF and Cu, CuF₂, LiF and Ni, NiF₂ or a combinationthereof.

As used herein, “intercalation chemistry material,” refers to a materialthat undergoes a lithium insertion reaction during the charging anddischarging cycles of a secondary battery. For example, intercalationchemistry materials include LiFePO₄ and LiCoO₂. In these materials, Li+inserts into and also deintercalates out of the intercalation materialduring the discharging and charging cycles of a secondary battery.

FIG. 1A is a simplified diagram illustrating a thermal management systemaccording to an embodiment set forth herein. As shown in FIG. 1A, theshared thermal management system 100 of a vehicle comprises variouscomponents for managing thermal profiles of combustion engine 101 andbattery system 105. For example, the combustion engine 101 can be aninternal combustion engine (e.g., gasoline, diesel engine, etc.) orother types of engine, where a large amount of heat is dissipated duringoperation. In some examples, the internal combustion engine can besubstituted for a fuel cell. In some of these examples, fuel cells areselected from cells having a proton exchange membrane (PEM). Typically,a large radiator is needed to dissipate the heat generated by thecombustion engine 101. The battery system 105, among other features, isconfigured to power electrical components of the vehicles. In variousembodiments, the vehicle is hybrid and relies on both combustion engine101 and an electric motor (not shown), and the electric motor is attimes powered by the battery module 105. In low temperature (typicallyaround or below freezing), the battery module 105 may have reducedperformance. It is common practice in plug-in hybrid electric vehiclesfor the combustion engine 101 to power the vehicle when the batterymodule is soaked to a low temperature. The heat dissipated by thecombustion engine 101 is transferred to the battery module 105 through ashared thermal path. As shown, the shared thermal circuit comprisespumps 102 and 106, valves 103, 108, 107, and 110. Additionally, heater104 and external exchanger 111 are also parts of the shared thermalpath. For example, the heater 104 and heater high voltage (HV) switch109 are implemented with an electrical heater, which is powered by thebattery module. The electric heater may be powered by the combustionengine 101 through a motor module that converts the power generated bythe combustion engine 101 to electricity for powering the electricheater. Other implementations are possible as well. Heat transfer fluidfacilitates heat transfer from the combustion engine 101 to the batterysystem 105, and vice versa. For example, in the cold-start scenariodescribed above, heat generated by the combustion engine 101 is absorbedby the heat transfer fluid and pumped by the pump 102 to the batterymodule 105. The valves as shown in FIG. 1A are connected to a controlsystem. In a cold start scenario, the valves only allow heated fluid totransfer from the combustion engine 101 to the battery module 105, andthe heat transfer fluid bypasses the external heat exchanger in ordernot to lose thermal energy to the outside environment. FIG. 1B shows anembodiment in which the heater 104 (and accompanying switch 109) areoptional and absent. In some examples, external exchanger 111 cancomprise one, two, or more heat exchangers thermally linked, connected,or combined.

As mentioned above, the battery system 105 comprises battery cellscapable of operating at high temperature. For example, the batterysystem 105, with its own significant thermal mass, can provide a heatreservoir to facilitate cooling of the combustion engine 101, instead ofusing the external heat exchanger. The method of cooling the combustionengine has the advantage that no external airflow or fans are required,allowing the vehicle to maintain optimum aerodynamic shape.

In certain applications, the battery module 105 can be configured tofacilitate warming of the combustion engine 101. For example, thecombustion engine 101 may be a diesel engine, which can be challengingto start in low temperature. In certain implementations, the combustionengine 101 may be warmed in advance of operation to reduce emissions andimprove performance before operation. In a specific embodiment, thecombustion engine 101 may be an internal combustion engine of a plug-inhybrid vehicle. In plug-in hybrid vehicles, the ICE often may not bestarted when the vehicle is first operated as the battery can providethe energy to power the vehicle for a certain distance (e.g. 10, 20, 30or more miles). It is to be appreciated that there is a challenge ofoperating the ICE when it is cold with full performance and meeting allrequirements (such as emission standards). In this use case, the batterymodule 105 warms up to a high temperature while powering the vehicle,and subsequently, while pump 106 is on, valves 107 and 103 are actuatedto thermally couple the battery system to the ICE and to pre-warm thecombustion engine 101 in advance of its operation. This process allowsthe engine to start operating at a warmer temperature, reducingemissions and improving performance. Another benefit is reduced wear andtear on the engine.

As another example, the same operation can be used by the battery system302 shown in FIG. 3A to obtain cooling by dissipating heat into theengine 306. Internal combustion engines typically weighs hundreds ofpounds, and thus have a high heat capacity. In some use cases, thetemperature of the combustion engine 306 may be lower than thetemperature of the battery module 302 and lower than ambienttemperature. In some examples, so long as the battery is warmer than theICE, the ICE may be used as a thermal sink. In those cases, batterysystem 302 can be cooled by transferring heat to the engine 306, with orwithout the use of the external heat exchanger 307. Utilizing thethermal mass of the internal combustion engine 306 for heat removal maybe more effective than heat dissipation through the external heatexchanger 307.

Now referring back to FIG. 1A. The heat generated by the battery system105 can be used by the climate control module of the vehicle to provideheating for the interior of the vehicle. In addition to the heatdissipation of the combustion engine 101, the heat dissipated by thebattery module 105 can be used for heating the vehicle interior, whichis, in some examples, useful when the combustion engine 101 is notoperating or in an electric vehicle without a combustion engine, asshown in FIG. 8A. In some examples, the interior of the car is heatedusing the waste heat dissipated by the battery. This example isbeneficial because it efficiently utilizes wasted heat from the batteryas useful heat for the interior of the car. In other examples, thebattery is used to power a heater which, in turn, is used to heat theinterior of the car.

It is to be appreciated that thermal system illustrated in FIG. 3A has ashared thermal path, wherein various heat-generating components cantransfer heat to one another and to the external heat exchanger using asingle thermal path. In certain embodiments, various components shown inFIG. 3A can operate at a high temperature (e.g., up to 150° C.). Forexample, when the ICE operates during hot ambient temperature, the heattransfer fluid (e.g., coolant) can reach over 100° C. before reachingthe radiator for heat dissipation. Various components shown in FIG. 3Acan have different operating temperature ranges. Thus, components in ashared thermal loop may be located specifically so as to match theiroperating temperatures and optimize the system. While FIG. 3A shows onlyone possible arrangement of components, other configurations arepossible (see FIG. 3C, for example, in which the electric motor 305 andICE 306 are in direct thermal communication). FIG. 3B, for example,shows an embodiment in which the heater 301 is optional. In a specificembodiment, the battery system is capable of operating at a temperatureof up to about 150° C.

FIG. 2 is a simplified diagram illustrating an alternative thermalmanagement system according to an embodiment set forth herein. Thethermal management system 200 includes an HV switch 201 that controlsthe heater 207. For example, the HV switch is coupled to a controlsystem. The battery module 206 is thermally coupled to the thermalcircuit and the components linked thereto by the pump 205, which pumpsheated fluid from the battery module to the combustion engine 202 asneeded. It is to be appreciated that the pumps as shown may beimplemented using a plurality of pumping devices. For example, multiplepumps devices may be coupled to one another in series to implement thepump 205. By having more than one pump to carry the pumping function, itprovides redundancy in case of pump failure. In addition, the placementof pumps can be configured to reduce the risk of failures. For example,pumps may be positioned before heaters and heat generating components.In a specific embodiment, the pump 203 is placed on the left side of thecombustion engine to pump heat transfer fluid to the combustion engine202. The valves 204, 211, 209, and 210 help control the flow of heattransfer fluid. For example, the valves may be implemented using varioustypes of switches. For example, pump and valve configurations andimplementations are described in U.S. patent application Ser. No.13/428,269, filed 23 Mar. 2013, entitled “Thermal Management System withDual Mode Coolant Loops”, now U.S. Pat. No. 8,402,776, and published asUS 2012-0183815 A1, which is incorporated by reference herein. It is tobe appreciated that thermal system illustrated in FIG. 2 has a sharedthermal path, wherein various heat-generating elements can transfer heatto one another using the shared thermal path.

FIG. 3A is a simplified diagram illustrating a thermal management systemin series configuration according to an embodiment set forth herein. Itis to be appreciated that the system shown in FIG. 3A allows the batterysystem, internal combustion engine, electric motor, motor electronics,and/or optionally other components to share a single thermal system,which includes a heat transfer circuit, a heat exchanger, and a pumpingdevice. As an example, in the embodiment shown in FIG. 3A, all thermalelements are configured in series. More specifically, the heater 301,the battery module 302, pump 303, motor electronics 304, electric motor305, the combustion engine 306, and the external heat exchanger 307 arein a series configuration as a part of the thermal circuit. Otherarrangements with certain components connected in series and in parallelare possible. It is to be noted that one or more components in thecircuit can be configured with a bypass to prevent heating or coolingit.

FIG. 4A is a simplified diagram illustrating operation of a thermalmanagement system where engine heat is used by a battery systemaccording to an embodiment set forth herein. As shown in FIG. 4A, thecombustion engine 401, the pump 402, the valve 403, the heater 404, thebattery module 405, the pump 407, and the valve 409 form one of severalthermal circuits. In some examples, the heater is not operating. Forexample, when the battery system is at a low temperature, if thecombustion engine 401 is operating, the heat generated by the combustionengine 401 can be transferred to the battery system 405 to warm up thebattery cells. As another example, if the battery system 405 is at ahigh temperature and the combustion engine 401 needs to be heated, theheat is transferred from the battery system 405 to the combustionengine. Depending on the application, the heater 404 can be operating,in which case the heat generated by the heater 404 is used to warm upboth the battery system 405 and, optionally, the combustion engine 401.It is to be appreciated that in this embodiment, the battery system candissipate heat into the engine as desired to utilize lower temperatureworking fluid in the engine and/or the engine thermal mass as analternative to the heat exchanger. FIG. 4B illustrates one possible flowpattern, for example.

FIG. 5A is a simplified diagram illustrating operation of a thermalmanagement system without using a heat exchanger according to anembodiment set forth herein. As shown in FIG. 5A, the battery module 505is in a closed loop with the heater 504. For example, the valves 507,510, 508 and 503 can be configured to, as needed, disengage thermalcoupling between the battery system 505 and the combustion engine 501.As an example, in this use case heater is turned on, and battery systemcan be heated using the heater, without any thermal energy being lost tothe combustion engine or to the external heat exchanger. In someexamples, circulating heat transfer fluid through the battery system viapump 506 as shown in FIG. 5A, with the heater turned off, equalizes thetemperatures of individual cells within the battery system, improvingperformance and prolonging life of cells in the battery system. It is tobe appreciated that other modes of operation are possible as well withthe system 500. FIG. 5B illustrates one possible flow pattern, forexample.

FIG. 6A is a simplified diagram illustrating operation of a thermalmanagement system where battery module heat is rejected via externalexchanger according to an embodiment set forth herein. As shown in FIG.6A, the battery module 605 is thermally coupled to the externalexchanger 609. The external exchanger 609 and the battery module 605 arethermally isolated from the combustion engine 601. It is to beappreciated that other modes of operation are possible as well with thesystem 600. FIG. 6B illustrates one possible flow pattern, for example.

FIG. 7A is a simplified diagram illustrating operation of a thermalmanagement system in an electric vehicle according to an embodiment setforth herein. It is to be appreciated that, as shown in FIG. 7A, thebattery system, electric motor (optionally), motor electronics(optionally), and/or other component/s are part of a single thermalcircuit and could be operated with only a single pump. For example, heatfrom all components sharing the thermal circuit can be rejected via asingle external heat exchanger. There are benefits stemming from such asimplified thermal system enabled by a single thermal circuit formultiple components: utilizing only a single pump, single heat exchangerand a single thermal circuit reduces the number of components in thevehicle, reducing cost, complexity, and volume used in the vehicle. FIG.7B illustrates one possible flow pattern, for example.

FIG. 8A is a simplified diagram illustrating operation of a thermalmanagement system with a shared thermal circuit having a climate controlmodule according to an embodiment set forth herein. In the thermalmanagement system shown in FIG. 8A, thermal energy from anyheat-generating devices, including the battery module, electric motorand motor electronics, is collected in a single thermal circuit thatincludes a thermal connection to cabin climate control. An advantage ofsuch an arrangement is that heat is collected from all possible sources,maximizing the temperature of the heat transfer fluid when it enterscabin climate control module 811. This allows fast warm-up of thepowertrain components in cold soak conditions and heat transfer to thecabin, improving overall vehicle efficiency. Such a system configurationcould be controlled as desired to bypass any devices at a lowertemperature in order to collect heat from devices at a temperature abovea threshold temperature, in order not to lose heat energy to devicesunnecessarily. FIG. 8B illustrates one possible flow pattern, forexample.

FIG. 9A is a simplified diagram illustrating thermal management systemoperating in a bypass mode from the heat exchanger module according toan embodiment set forth herein. As shown in FIG. 9A, when the heattransfer fluid flow bypasses the external heat exchanger 909, thethermal management system has the advantage that heat from all thecomponents in the circuit, such as the electric motor 905, motorelectronics 907 and other heat-releasing components can be used to warmup the battery system 903. Alternatively, heat from the battery system903 could warm up the motor electronics 907 and/or electric motor 905.Another benefit of such an arrangement is that temperature is naturallyequalized between all the devices in the thermal circuit. FIG. 9Billustrates one possible flow pattern, for example.

FIG. 10A is a simplified diagram illustrating operation of a thermalmanagement system with bidirectional flow control according to anembodiment set forth herein. As shown in FIG. 10A, the thermalmanagement system, in some examples, has a plurality of pumps arrangedsuch that the flow of the heat transfer fluid is bidirectional, or asingle pumping device capable of pumping in both directions. Dependingon the implementation, the embodiment can have several advantages overuni-directional pumping: heat can be transferred from battery system tothe motor (and/or other components in the circuit) if the battery systemis at an elevated temperature or from the motor (or other components inthe circuit) to the battery system, if desired. Another benefit ofbi-directional flow includes improved thermal management of batterysystem. Battery cells typically suffer premature degradation becauseheat is rejected preferentially from a single side of the batterysystem, due to flow from a single direction. The ability to reverse theflow allows for even cooling of each side of the battery system,prolonging life of the battery system. It is to be appreciated that in athermal system circuit with a single external heat exchanger and withoutadditional heat-accepting devices, the thermal fluid typically has thelowest temperature immediately after flowing through the heat exchanger.Another benefit of the bi-directional operation is that either of thedevices thermally adjacent to the heat exchanger can be selectivelycooled with the lowest temperature heat transfer fluid, maximizing theeffectiveness of the cooling system. FIG. 10B illustrates possible flowpatterns, for example.

FIG. 11A is a simplified diagram illustrating a thermal managementsystem where one group of powertrain components can be thermallyseparated from a second group of components according to an embodimentset forth herein. In some examples, that components shown in FIG. 11Ahave different operating temperature ranges. In certain examples,electric motor and motor electronics may operate at temperature rangeslower than ICE and/or battery system. In some examples, componentsoperating at a relatively low temperature range are thermally coupled toone another in a “low-temperature” thermal loop, and the componentsoperating at relatively high temperature range are thermally to oneanother in a “high-temperature” thermal loop. In some examples, acontrol system determines whether to merge operation back into a singlethermal circuit. FIG. 11C shows an alternate component arrangement, asan example. In FIG. 11A, the thermal management system includes of athermal circuit which can be thermally separated into a first thermalpath for first group of powertrain components (i.e. battery system 1101and internal combustion engine 1113) and second thermal path for secondgroup of powertrain components (i.e. electric motor 1104 and inverter1105) according to an embodiment set forth herein. The thermalseparation may be achieved by control of valves such as 1102, 1103, 1106and 1109. FIGS. 11B and 11D show options without a heater. Thesearrangements have the advantage that most or all of the powertraincomponents can be thermally managed with a single thermal circuit, butcan also be thermally separated in conditions where different thermalproperties (i.e. temperature) are needed for different components. Onepotential beneficial use case is that when combustion engine is off, allthe powertrain components are cooled with a single loop. If thecombustion engine is turned on, and the temperature of the thermal fluidin the circuit rises above a predetermined threshold, components thatrequire a lower operating temperature can be thermally disconnected fromthe loop.

In some examples, set forth herein is a thermal management system for avehicle with an electric drivetrain. In these examples, the systemincludes a battery system having at least one battery cell. In someexamples, the battery cell has, in some examples, a cycle life of atleast 100 cycles. In certain examples, the battery cell has an optimaloperating temperature of about 40° C. or higher. In certain examples,the battery cell has an optimal operating temperature of about 45° C. orhigher. In certain examples, the battery cell has an optimal operatingtemperature of about 50° C. or higher. In certain examples, the batterycell has an optimal operating temperature of about 55° C. or higher. Incertain examples, the battery cell has an optimal operating temperatureof about 60° C. or higher. In certain examples, the battery cell has anoptimal operating temperature of about 65° C. or higher. In certainexamples, the battery cell has an optimal operating temperature of about70° C. or higher. In certain examples, the battery cell has an optimaloperating temperature of about 75° C. or higher. In certain examples,the battery cell has an optimal operating temperature of about 80° C. orhigher. In certain examples, the battery cell has an optimal operatingtemperature of about 90° C. or higher. In certain examples, the batterycell has an optimal operating temperature of about 100° C. or higher. Incertain examples, the battery cell has an optimal operating temperatureof about 105° C. or higher. In certain examples, the battery cell has anoptimal operating temperature of about 110° C. or higher. In certainexamples, the battery cell has an optimal operating temperature of about115° C. or higher. In certain examples, the battery cell has an optimaloperating temperature of about 120° C. or higher. In certain examples,the battery cell has an optimal operating temperature of about 125° C.or higher.

In some of the above examples, the system also includes an internalcombustion engine (ICE).

In some of the above examples, the system also includes a shared thermalcircuit thermally coupling the battery system and the ICE, including aworking fluid, at least one switch or valve for controlling the transferof the working fluid, and at least one external heat exchanger.

In some of the above examples, the system also includes a control systemfor controlling the heat exchange between the ICE and the batterysystem, wherein the control system actuates the at least one switch orvalve.

As illustrated in FIG. 1A, in some examples, the system includes abattery system 105 in serial connection with a pump 106 and a heater104. In some of these examples, the battery system can be warmed by theheater. In some of these examples, the battery can power the heater. Insome other examples, an ICE can power the heater which can warm thebattery system 105. In some examples, a heat exchanger can be seriallyconnected to the battery, depending on the valves actuated (e.g., 107and 110) in order to exchange heat from the battery system 105 or fromthe ICE 101. Depending on the valves which are actuated (e.g., 107, 108,103, and 110), the working fluid can be circulated between the ICE 101and the battery system 105 or optionally also to the external exchanger.

As illustrated in FIG. 1B, in some examples, the system does not includeheater 104 but does include the aforementioned components.

As illustrated in FIG. 3A, 3B, or 3C, in some examples, the ICE 306,electric motor 305, and motor electronics 304 can be serially connectedwithin the thermal circuit. In some examples, the working fluid thatcontacts the battery system can be transferred to or from the ICE 306,electric motor 305, and motor electronics 304 depending on the valves(V) which are activated and depending on the operation of pump 303.

As illustrated in FIG. 4B, in some examples, the working fluid can betransferred from the battery system 405 to the ICE 401 withoutcontacting the external exchanger 411. In some other examples, valves409 and 410 can be actuated to also allow the working fluid to contactthe external exchanger.

As illustrated in FIG. 5B, in some examples, the working fluid can becirculated around the battery system 505 but without contacting theexternal exchanger 505 or the ICE 501, depending on the operation ofpump 506 and valves 507 and 510.

As illustrated in FIG. 6B, in some of the above examples, the workingfluid can also be circulated through the external exchanger 609depending on the actuation of valve 610.

As illustrated in FIG. 8B, in some of the thermal management systemsdescribed here, such as the system of FIG. 8A, the working fluid canalso be circulated through the battery system 803, motor electronics805, electric motor 806, cabin climate control 811 but not through theexternal exchanger 809.

As illustrated in FIG. 9B, in some of the thermal management systemsdescribed here, such as the system of FIG. 9A, the working fluid can becirculated through the battery system 903, motor electronics 907,electric motor 905, cabin climate control 811 but not through theexternal exchanger 909.

As illustrated in FIG. 10B, in some of the thermal management systemsdescribed here, such as the system of FIG. 10A, the working fluid canalso be circulated in a bi-directional flow pattern through a batterysystem 1001, at least one or more pumps, motor electronics 1005,electric motor 1007, combustion engine 1009, and external exchanger1011.

As illustrated in FIG. 11A, in some examples, the thermal managementsystems includes a battery system 1101 on a thermal loop that alsoincludes an ICE 1113 and which is separate from a thermal loop thatincludes the motor electronics 1105 and electric motor 1104. Dependingon the actuation of valves 1103, 1102, 1109, or 1106, these componentscan be thermally isolated or thermally coupled with each other. Asillustrated in FIG. 11B, in some examples, the heater is not included inthe thermal management system. As illustrated in FIG. 11C, in someexamples, the thermal management systems includes a battery system 1101on a thermal loop that also includes the motor electronics 1105 andelectric motor 1104 and which is separate from a thermal loop thatincludes an ICE 1113. Depending on the actuation of valves 1103, 1102,1109, or 1106, these components can be thermally isolated or thermallycoupled with each other. As illustrated in FIG. 11D, in some examples,the heater is not included in the thermal management system.

EXAMPLES Conventional Plug-In Hybrid Electric Vehicle (PHEV) Example

In one example, a PHEV with an 85 hp (63 kW) internal combustion engine,120 kW electric motor, and a 16 kWh battery system was used. Theinternal combustion engine and battery system were each on separatethermal management loops each including a pump and radiator. 30 kW ofdrive power was employed, in which the internal combustion engine had a33% rejection rate of heat into the coolant loop (i.e. 10 kW at 30 kWdrive power). The battery system thermal management loop also featured a5 kW heater.

The 16 kWh battery system featured lithium ion cells that have agravimetric energy density of 200 Wh/kg and a total cell weight of 80kg. Cell specific heat capacity was 1KJ/kg ° C. Cell & module heatcapacity was 106 KJ /° C.

The pump for this independent battery thermal management loop weighed 1kg, took up 1.5 L of space, and cost $100. The radiator for theindependent battery thermal management loop weighed 0.5 kg, took up 3.5L of space, and cost $75. The heater for the battery thermal managementloop weighed 7 kg, took up 10 L of space, and cost $100.

A −10° C. cold soak was used for the battery system and the internalcombustion engine operated the car until the battery system was at 90%of cell power capability. The 5 kW heater warmed the battery modules to˜20° C. in approximately 10 minutes, enabling 90% of the cells peakpower rating. Heating in the above example off the electric heater aloneconsumed 3000 kJ or 0.8 kWh of system energy.

TABLE 1 Heating Time 1 10 30 1 2 5 10 Typical Li-Ion cells: secondseconds seconds minute minutes minutes minutes Heater Energy Output (kJ)5 50 150 300 600 1500 3000 Cell Temperature Increase 0.05 0.47 1.41 2.825.64 15.10 28.20 (degrees Celsius) Battery System Temperature −10.0 −9.5−8.6 −7.2 −4.4 4.1 18.2 (deg C.) Approximate Battery System 18% 18% 18%20% 25% 45% 90% Rate Capability (% of peak) Battery System Power 21.621.6 21.6 24 30 54 108 Capability (kW)

Shared Thermal Management PHEV Example

In a second example, a PHEV with an 85 hp (63 kW) internal combustionengine, 120 kW electric motor, and a 16 kWh battery system was used. Theinternal combustion engine and battery system were on a shared thermalmanagement loop as described in this disclosure.

The 16 kWh battery system featured lithium ion cells that have agravimetric energy density of 200 Wh/kg and a total cell weight of 80kg. Cell specific heat capacity was 1 KJ/kg ° C. Cell & module heatcapacity was 106 KJ/° C.

With this implementation of the shared thermal management systemcompared to the conventional example, no independent pump or radiatorwas required for the battery system. Furthermore, no heater wasrequired. Consequently, this saves an aggregate 8.5 kg, 15 L of space,and $275 of cost. Expressed per kWh of battery system, this cost savingswas about $17/kWh.

A −10° C. cold soak was used for the battery system with the internalcombustion engine operating the car until the battery system was at 90%of cell power capability, the 10 kW of “waste heat” from the internalcombustion engine was transferred via the shared thermal management loopto warm the battery modules to ˜20° C. in approximately 5 minutes,enabling 90% of the cells peak power rating. Relative to the“conventional PHEV” example above, the warm time to 90% of cell powercapability was achieved in half the time (i.e. 5 minutes faster) andwithout the expenditure of 0.8 kWh of battery system capacity (5% ofsystem capacity) which at 250 Wh/mile represents 3.3 miles of electricrange.

TABLE 2 Heating Time Typical Li-Ion cells: 1 second 10 seconds 30seconds 1 minute 2 minutes 5 minutes Cumulative ICE Heat 10 100 300 6001200 3000 Rejected into Coolant (kJ) Cell Temperature Increase 0.09 0.942.82 5.64 11.28 28.20 (degrees Celsius) Battery System Temperature −9.9−9.1 −7.2 −4.4 1.3 18.2 (deg C) Approximate Battery System 18% 18% 18%25% 40% 90% Rate Capability (% of peak) Battery System Power 21.6 21.621.6 30 48 108 Capability (kW)

The above description is presented to enable one of ordinary skill inthe art to make use of disclosures herein and to incorporate them in thecontext of particular applications. Various modifications, as well as avariety of uses in different applications will be readily apparent tothose skilled in the art, and the general principles defined herein maybe applied to a wide range of embodiments. Thus, the disclosure setforth herein is not intended to be limited to the embodiments presented,but is to be accorded the widest scope consistent with the principlesand novel features disclosed herein.

It is to be appreciated that embodiments set forth herein providenumerous advantages over existing technologies. Examples of improvementsinclude but are not limited to reduced component costs, lower weight,lower volume, higher reliability, longer life, higher performance,higher efficiency, and a reduction in complexity. There are otherbenefits as well.

What is claimed is:
 1. A thermal management system for a vehicle with anelectric drivetrain, the system comprising: a battery system comprisingat least one battery cell having a cycle life of at least 100 cycles,and an optimal operating temperature of about 75° C. or higher; aninternal combustion engine (ICE); a shared thermal circuit thermallycoupling the battery system and the ICE, comprising: a working fluid, atleast one switch or valve for controlling the transfer of the workingfluid, and at least one external heat exchanger; and a control systemfor controlling the heat exchange between the ICE and the batterysystem, wherein the control system actuates the at least one switch orvalve.
 2. The system of claim 1, wherein the control system is selectedfrom a computer, a programmed chip, a microprocessor, or a logiccircuit.
 3. The system of any one of claims 1-2 further comprising atleast one electric motor or generator connected to the shared thermalcircuit.
 4. The system of any one of claims 1-3 wherein the vehicle is ahybrid electric vehicle comprising an ICE and an electric motor.
 5. Thesystem of any one of claims 1-4 further comprising motor powerelectronics thermally coupled to the shared thermal circuit.
 6. Thesystem of any one of claims 1-5 further comprising a battery systemcharger.
 7. The system of any one of claims 1-6 wherein the thermalmanagement system is configured to dissipate heat from devices connectedto the shared thermal circuit via the external heat exchanger.
 8. Thesystem of any one of claims 1-7 wherein the battery system has a cyclelife of at least 100 cycles and is capable of operating at a temperatureof 85° C. or higher.
 9. The system of any one of claims 1-8 wherein theoptimal operation comprises greater than 50% power output from thebattery relative to the rated power output of the battery.
 10. Thesystem of any one of claims 1-9 wherein the battery system is configuredto start the ICE.
 11. The system of any one of claims 1-10 wherein thebattery system further comprises thermal insulation.
 12. The system ofany one of claims 1-11 wherein the control system controls the transferof the working fluid such that heat dissipated by the battery systemtransfers to one or more components on the shared thermal circuit, whichare at a lower temperature than the battery system.
 13. The system ofany one of claims 1-12 further comprising a climate control module,wherein heat generated by the battery system or other components in theshared thermal circuit transfers to the interior of the vehicle.
 14. Thesystem of any one of claims 1-13 wherein the battery system comprises anenclosure, the enclosure having a floor surface thermally coupled to theshared thermal circuit and the external environment, the enclosure floorsurface being configured to transfer heat between thermal fluid and theexternal environment.
 15. A thermal management system for a vehicle withan electric drivetrain, the system comprising: a battery systemcomprising at least one battery cell having a cycle life of at least 100cycles, and an optimal operating temperature between about 75° C. orhigher; a shared thermal circuit thermally coupling the battery systemand vehicle components coupled to the thermal circuit, comprising: aworking fluid, at least one switch or valve for controlling the transferof the working fluid, wherein a control system actuates the at least oneswitch or valve, and at least one external heat exchanger; and a controlsystem for controlling the heat exchange between the battery system andthe other components coupled to the thermal circuit.
 16. The system ofany one of claims 1-15, wherein the thermal circuit further comprises afluid transfer module configured to operate based on signals receivedfrom the control system.
 17. The system of any one of claims 1-16,further comprising a powertrain or powertrain component thermallycoupled to the shared thermal circuit.
 18. The system of any one ofclaims 1-17, wherein the external heat exchanger comprises one or moreheat rejection devices configured to dissipate heat away from thethermal management system.
 19. The system of any one of claims 1-18,comprising a single thermal circuit, a single pumping device, and asingle external heat exchanger.
 20. The system of any one of claims1-19, wherein the battery system is characterized by a cycle life of atleast 100 cycles and an optimal operating temperature of about 85° C. orhigher.
 21. The system of any one of claims 1-20 wherein the sharedthermal circuit comprises one or more pumping devices for transferringthe working fluid in either direction within the circuit.
 22. The systemof any one of claims 1-21, wherein the control system is capable ofcausing the heat dissipated from a powertrain component to transfer tothe battery module if the battery module is lower than a predeterminedtemperature.
 23. The system of claim 22, wherein the predeterminedtemperature is 75° C.
 24. The system of any one of claims 1-21,comprising a powertrain component having an electric motor.
 25. Thesystem of any one of claims 15-24, wherein the vehicle does not comprisean internal combustion engine.
 26. The system of any one of claims 1-24and substantially as shown in FIG. 1A, 1B, 2, 3A, 3B, 3C, 4A, 4B, 5A,5B, 6A, 6B, 7A, 7B, 8A, 8B, 9A, 9B, 10A, 10B, 11A, 11B, 11C, or 11D.